In drag racing, the objective is to complete the short track race before a competitor while, at the same time, maintaining a total race time which does not fall under a preset minimum time. This preset time is typically referred to as an index time and is established to ensure close results between competitors. If a car completes the race in a time under the index time, the racer is declared the loser by disqualification.
As described in prior art Noe et al. U.S. Pat. No. 4,784,099, drag racing vehicles are typically designed to run faster than the allotted index time if the vehicle is maintained at full throttle. Designing the vehicle with a speed capacity which would allow it to complete a race under the allotted index time guarantees that the vehicle will have sufficient power (and speed) under all racing conditions. However, this excess power must be controlled so as to complete the race in a total time in excess of the allotted index time, thereby avoiding disqualification.
The Noe et al. prior art reference describes a specific example of what is commonly referred to as a two-stage (or dual stage) throttle stop controller. In essence, the throttle, while wide open at launch to reach maximum acceleration, will be closed for a period of time during the race so that the car does not run at an overall speed quicker than the allotted index time would allow.
Two-stage throttle stop controllers are operated by setting two timers prior to launch. Launch is generally understood to refer to the time the vehicle begins forward acceleration. The two timers begin to run upon launch of the vehicle. When the first timer expires, the throttle will be shut. Upon expiration of the second timer, the throttle will again be opened as it was at launch. Obviously, the difference between the values preset in the first and second timers is equivalent to the time in which the throttle will be closed. The result of such a two-stage throttle is a vehicle which launches at full throttle (for the lowest reaction time), reduces power at mid-track, and then reaches maximum power once again for the end of race ("top-end") charge. In reality, then, the term "two-stage" throttle controller is a misnomer since three separate stages (full throttle, closed throttle, followed by full throttle) are actually achieved.
More recently, four-stage controllers have been incorporated and approved by the National Hot Rod Association ("NHRA"). A four-stage throttle controller uses four timers which result in two separate periods during the race (after launch) in which the throttle will be closed. The main purpose of the second period of time during which the throttle is closed (a duration equal to the difference between the third and fourth timers), which is programmed to occur near the finish line, is to confuse your opponent into thinking there is a risk of running under the allotted index time. Ideally, your opponent would jam on his/her brake to avoid such a disqualification, your fourth timer would expire thus reopening your throttle, thereby permitting you to cruise to victory.
Whether a two-stage throttle controller, a four-stage throttler controller, or some other variation throttle controller is incorporated, the significant factor is when, and for what length of time, the throttle will be closed or, in other words, what values the timers are set. In present day drag racing vehicles, these values are predetermined prior to launch based on anticipated race conditions, including the anticipated speed of the vehicle. Unfortunately, actual race conditions (and speed) rarely match what was anticipated.
Of course, one significant factor in determining the victor in a drag race is the reaction time at the start. The activation of the starting lights is typically referred to as "stages" and precedes the time of launch. During the time between stage and launch, the throttle is open, but a transbrake is set thereby preventing forward acceleration. New delay boxes can calculate pre-launch factors thereby modifying the time between stage and launch. One specific type of delay box is described in Reid U.S. Pat. No. Re. 32,474. While modification in the launch time will effect the initiation of the decrementing of the timers in the throttle controller, the throttle actually stays on and off subsequent to launch for the same period of time. However, even if such delay boxes, which control pre-launch calculations, could calculate certain pre-launch factors rapidly enough to adjust the values of the timers in the throttle controller, this would be of no use to the driver who encounters post-launch factors such as tire slippage (which will, of course, slow the vehicle), excessively good tire traction (which, of course, will result in a race time under the allotted index time), etc.
In view of the aforementioned and other deficiencies in the prior art, it is therefore an object of the present invention to provide a new and improved time operated throttle and method which can modify the operation of the throttle based on post-launch conditions.
It is yet another object of the present invention to provide a new and improved time operated throttle and method whereby the modification to the operation of the throttle can be controlled by a driver based on post-launch conditions.
Further objects and advantages of the present invention will become apparent as the following description proceeds.